Note: This post was originally published in 2010 - I thought it would be useful to republish it because the subject continues to be something many people don't fully understand.
I often here people talk about how many "hits" they get on their Website and it's time to tell them they don't know what they are talking about. What is a hit?
A hit is the transfer of a single file from one computer to another
To fully understand this you need to know how your computer views a Webpage. When you are online and you click on a link your computer does one simple thing; it retrieves the page you want from the location as defined by the link you just clicked.
Normally the page is somewhere on the Internet (versus on your local hard drive) and having located the page it downloads it to your personal computer.
Each Web page is made up of two primary things; the page itself and any files displayed or referenced by that page. A 'hit' is recorded for the download of that specific page and every file downloaded with it.
As an example let's look at the home page of this blog. It references 26 images and then there's the page itself so every time someone looks at the home page they download 27 files (1 html page plus 26 images). This translates to 27 hits. As a result if ten people look at the home page we record 270 hits.
There is no limit to the number of images a Webpage can reference. This means that a Webpage with a hundred images, looked at by the same ten people (once), will generate 1,000 hits. If you consider that in all likelihood they will click from the home page to several other pages on the same Website it is possible for one person, on a graphically intensive Website, to generate thousands of hits.
In simple terms a hit is a totally useless piece of data.
AgencyLogic single property Websites provide the most detailed usage statistics available and yes we provide data on the number of hits. Why? Because our clients want the information and we give them what they want. We also try to explain why they should focus on other more valuable metrics like page views and referring sites and people.
Dependent on the statistics package you use things can get a little more complex. Some files may be included or ignored based upon their location again skewing the numbers. Some Webpages use CSS (Cascading Style Sheets) and seperately might reference images on someone elses server. The amazing thing is that html combined with your Web browser allows you to download information, images and files in seconds, simultaneously from multiple sources on the Internet, then renders (displays) everything to make it all look pretty.
I hope this helps :)